Fig. 5.2.

Habitat specialisation occurs at a range of spatial scales. Obligate specialists may associate with a specific range of hard branching coral species such as the goby Gobiodon histro with coral Acropora nasauta (A) and Gobiodon citrinus also with A. nausata (B). They are never found in the absence of these coral species. Facultative specialists such as the damselfish Pomacentrus moluccensis (C) are found on a range of hard coral species and growth forms (D), and may even be found in areas devoid of hard corals. Generalists such as the wrasse Cheilinus digramma (E) are not typically associated with any particular coral type, but are generally found in areas that contain a range of different structural habitats (F) (Photos: A,B, P. Munday; C,E, Great Barrier Reef Marine Park Authority; D,F, Mike Kingsford).